Q's... Burner and TV Tuner/Adapter Use?



First off, I am not smart when it comes to technology and how to use it and I apologize in advance for any misconception, stupid question, and or lost time one receives if they are willing to help me.

By purchasing an external DVD burner, an external TV Tuner/adapter, and any necessary cables that would be needed, would I be able to hook up the DVD burner to a computer and receive an:

  1. input from a VCR that can be transfered to the burner in DVD-like quality
  2. input from the computer it is attached to
  3. an input from a television signal/cable that can be tuned and transfered to the burner in DVD-like quality?

If step one makes sense… would there be any digital audio and video transferal/saving/etc. problems involved with a computer being used that does not have any special capacity to play video? (I assume the “streaming” [or whatever it is called] input could just be saved in high quality without running into any playback problems.)

If the above isn’t a problem… would I be able to play back the input signal - mainly to edit it - without any great amount of video viewing/running specs?

If the previous question indicates that nothing special would be required… how much hard drive space would I need or is it a question of memory or another element that I do not understand here

Thank you for any help.